Vuforia: How to hide terrain behind box-target?

I'm using Unity Extension for Vuforia. And I have a MultiTarget (box). As child of my MultiTarget, I have scene with terrain. But when target start tracking and scene appear terrain draw over box. But I tested other object on same level as terrain, and they hides behind box without problems. I want scene like this:

But I get view like this:

UPD: I try to use solution from http://answers.unity3d.com/questions/332479/hide-object-behind-imagetarget.html, but it didn't work. Maybe I make something wrong?